Improvement in combined chair and treadle-power



. J. B. UNDERWOOD. I Combined OhairandTreadle Power.

No. 209,842. Patented-Nov. '12, 1 878.

luvimnQ ATTORNEYS.

MPEIERS, PHUTO-LITHOGRAPNER, WASHINGTON. n c.

UN TED STATES PATENT @rnion.

JOSEPH B. UNDERVVOOD, OF FAYETIEVILLE, NORTH CAROLINA.

IMPROVEMENT IN COMBINED CHAIR AND TREADLE-POWER.

Specification forming part of Letters Patent No. 209,842, dated November12, 1878 application filed July 27', 1878.

To all whom it may concern: I

Be it known that I, J osEPH B. UNDEnwooD, of Fayetteville, in the countyof Cumberland and State of North Carolina, have invented a new andImproved Combined Chair and Treadle-Power; 1 and I do hereby declarethat the following is a full, clear, and exact description of the same,reference being had to the accompanying drawing, forming part of thisspecification, in which Figure 1 is a side elevation of the chairapplied to the frame-work of a sewing-machine. Fig. 2 shows, inperspective, a modification of the invention with means for adjustingthe chair vertically. Fig. 3 is a detail of the chairframe, showing,another arrangement for adjusting the chair vertically. Fig. 4 is a detail of the saddle.

The object of my invention is to reduce the muscular force exerted inrunning a sewingmachine or other device operated by a treadle, and totransfer the strain from the muscles of the abdomen and other partswhich are injuriously affected thereby to other muscles ,which are.better able to exert the power and withstand the fatigue, thus confiningthe work to the lower part of the legs, and converting a laborious andinjurious operation intoone of healthful exercise.

In securing this result my invention consists in so pivoting the chairand arranging itupon springs that it shall have a compound vibratorymotion, which adapts it to the movement of the operator, and utilizingthis movement by connecting with the chair 1 a pendent lever-frameprojecting from and rigidly attached to the chair, which frame convertsthe movement of the chair into a reciprocating movement of the treadlethrough a connecting-rod, and operates in conjunction with thenaturalfoot' movement upon the treadle, as hereinafter more fullydescribed.

In the drawing, A represents the frame, B the treadle-rod, G thetreadle, D the pitman, and E the crank-shaft, of an ordinary form ofsewing-machine, to which my invention is shown applied. F is the chair,and G G basebars, to which the hind legs of the chair are pivoted at a,which base-bars are extended in front beneath the treadle-rod, andprovided with notchesb to receive the treadle-rod and hold the chair inthe desired proximity to the treadle. Beneath the front legs of thechair are placed springs c c, which permit the chair to rock on itspivots a insupplying one of its movements. The chair seat and body arealso pivoted at d to the upper portion of the chair legs or-franle,which gives to the seat of the operator a second point of oscillation.Projecting downwardly from the chair-seat, and rigidly connectedtherewith, is a stiff leverframe, H, the lower end of which descends tothe level of the treadle, and is provided with adjusting-holes.

I is ahorizontal connecting-rod, secured adjustably to the lower end ofthe lever-frame by means of holes and a bolt, 0, and fastened at itsforward end to a projection from the lower side of the treadle.

In adapting this connection-rod I for easy attachment to the treadles ofvarious machines, I employ a saddle-plate, J, which consists of a platearched at f to pass around the treadlerod, and provided with flatbearing-faces upon opposite sides of said arched portion, which facesare perforated with numerous holes to permit the saddle to be bolted tothe under side of the treadle. Thenumerous perforations in thissaddle-plate and the open character of most treadles permit abinding-place for a bolt to be easily formed. From the under side ofthis saddle depends a projection, g, to which the front end of thehorizontal connecting-rod is loosely pivoted.

Now, the operator being seated in the chair and the point or front endof the treadle being elevated, as shown, the operation of the deviceswould be as follows:

When seated in the chair the center, of gravity of the operator is inthe rear of the chair-pivots d, and the chair-seat, by itsleverconnections with the projection on the bottom of the saddle,transmits its liftingeforce to the front side of the treadle, lifting upthe toe of the foot at the same time. -It will thus be seen that nomuscular effort whatever is required to depress the heel of the treadle.As

soon as the operator presses with the toe upon the treadle this pressurehas a tendency to depress the outer end or too of the'treadl'e. At thesame time, also, this muscular exertion throws the weight of the bodyupon the thighs and shifts the center of gravity to the front of thepivots (I, causing a compression of the springs, a rocking forward ofthe chair upon its leg-pivots a, and also a rocking forward of the chairupon its seat-pivots d. This action causes the lower end of thelever-frame and the connecting-rod to be drawn back, and produces aneffect upon the treadle, in conjunction with the toe-pressure, to bringthe toe of the treadle down.

In depressing the heel of the treadle the weight of the body is againshifted to the rear of the pivots (I, the chair moves backward on itspivots d and a, and the lower end of the lever-frame, in moving forward,produces an effect upon the treadle in harmony with the downwardmovement of the heel portion.

It will thus be seen that the chair moves in accordance with the naturaland easy movement of the lower part of the body in operatin g thetreadle, and not only automatically adjusts itself to the motion, butco-operates to drive the machine by its own movement. The chair is alsoso constructed that the great weight and powerful leverage of the bodyis kept in nice balance, so that the machine runs not only easier, butmore uniformly and without jerks. It will also be seen that the legs ofthe operator are not lifted up and down at an expense of muscular powerfrom the seat of the chair, as is the case in driving the treadle whenthe chair is rigid and stationary; but the chair follows and supportsthe legs with an easy rocking movement, which reduces the strain uponthe abdominal muscles and distributes it throughout the muscles of thelegs.

While the foregoing advantages are secured, the motion of the chair isnot sufficient to atfeet the position of the upper portion of the bodyat the table, a very slight movement of the seat of the chair beingsufficient, when multiplied by the lever-frame beneath, to produce thedesired effect.

In order to make the seat of the chair adjustable as to height fordifferent operators,

the chair-frame may be provided with a vertical groove or guide, h, (seeFig. 3,) on each side, in which a sliding and slotted bar, i, may beadjustably secured by a bolt passing through the slot and a perforationin the chairframe, the chair-seat having its pivot 11 at the top of thisslotted and adjustable bar 2'.

As a further means of adjustment, the arrangement shown in Fig. 2 may beused, in which the lever-frame is rigidly attached to a cross-bar, j,pivoted at d to the chair-frame, and the seat of the chair is providedwith a screw-stem, which turns in a female-screw in the said cross-barafter the manner of the ordinary adjustable office-chair.

The springs of the chair, instead of being placed beneath the frontlegs, as shown, may be placed at any point when they tend to rock thechair back on its pivots a.

I am aware of the patent to E. J. Leyburn, No. 94,618, in which asewing-machine frame is mounted upon a rockingchair, so as to beinseparable therefrom. This device, however, is not applicable to anddetachable from all kinds of treadle sewing-machines, and I thereforedisclaim it.

Having thus described my invention, what I claim as new is- 1. A chairhaving a compound rocking movement, connected to and combined with thetreadle of a sewing-machine or other mechanism, for the purpose ofutilizing the movement of the body to assist in driving the treadle.

2. A rockingchair having its seat pivoted to its legs, its front legsheld up by springs, and provided with a connection for the treadle of amachine, substantially as described.

3. A chair arranged to rock on its hind legs, and having a second set ofpivots for the seat, combined with the treadle, a connecting-rod, and aframe or projection rigidly attached to the chair-seat, and connectedwith said treadle by the connecting-rod, substantially as de-' scribed.

4. The base-bars G G, having notches b to receive the treadle-rod, incombination with the chair and sewing-machine, as described.

5. The saddle J, having in the middle an arch, f, with pendentprojection g, in combination with the treadle and a connecting-rot foropera-tin g the same, as described. a

6. The chair-seat pivoted at d to a rockingframe, and made verticallyadjustable, substantially as described.

7. The chair-seat pivoted at d, and having a pendent frame orprojection, in combination with the frame pivoted at its rear upon itslegs and sustained in front upon springs c 0, together with theconnecting-rod l and the treadle O, substantially as and for the purposedescribed.

JOSEPH B. UNDERWOOD.

Witnesses:

Gnu. P. MGNEILL, JosErI-I A. WORTH.

